Nanoparticle based inks and methods of making the same

Abstract

The present invention provides nanoparticle based recording mediums, inks and ink compositions, methods of making nanoparticle based recording mediums and inks, nanoparticles and methods for making nanoparticles, methods for stabilizing colorants against electromagnetic radiation (including radiation in the visible wavelength range), methods for enhancing the substrate independent durability performance of inks, and methods for color density control. The nanoparticle based inks deliver better color, color density control, improved printability, enhanced durability, and increased lightfastness, and are capable of being printed on woven and non-woven fabrics and paper products without special treatment or other limitations.

1 . A recording medium comprising a nanoparticle having a size of less than about 1,000 nanometers and comprising:
 a polymeric core having a positive or a negative zeta potential;   a first charged polymer layer disposed on the core and having a zeta potential different from the zeta potential of the core;   at least one successive charged polymer layer disposed on the first charged polymer layer, wherein the zeta potential of the at least one successive charged polymer layer is different from that of the charged polymer layer adjacent thereto; and   a carrier.   
   
   
       2 . A printing process comprising ejecting a recording medium in the form of droplets from an orifice in accordance with a recording signal to form an image on a substrate, the recording medium comprising:
 a nanoparticle having a size of less than about 1,000 nanometers and comprising a polymeric material having at least one colorant disposed within the polymeric material; and   a carrier.   
   
   
       3 . The printing process of  claim 2 , wherein the process is an ink-jet process. 
   
   
       4 . The printing process of  claim 2 , wherein the substrate is a textile, a cellulose, a paper, a ceramic, a polymer, a wood, or a glass. 
   
   
       5 . A printing process comprising ejecting a recording medium in the form of droplets from an orifice in accordance with a recording signal to form an image on a substrate, the recording medium comprising:
 a nanoparticle having a size of less than about 1,000 nanometers and comprising a polymeric material having at least one colorant disposed within the polymeric material;   a surface modifying layer disposed on and substantially covering the nanoparticle; and   a carrier.   
   
   
       6 . The printing process of  claim 5 , wherein the surface modifying layer comprises an agent selected from polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polysiloxane, polysiloxane polyethylene oxide copolymer, polysiloxane polypropylene oxide copolymer, linear dextrins, cyclodextrins, chitosans, or combinations thereof. 
   
   
       7 . A method of making a recording medium comprising:
 providing a plurality of particles comprising a polymeric core having an agent disposed within the polymer and at least one charged polymer layer disposed on and substantially covering the core;   providing a carrier; and   admixing the particles and the carrier.   
   
   
       8 . A method of making a recording medium comprising:
 providing a plurality of nanoparticles having a size of less than about 1,000 nanometers and comprising a polymeric material having at least one colorant disposed within the polymeric material;   providing a carrier; and   admixing the plurality of nanoparticles and the carrier.   
   
   
       9 . A method of making a recording medium comprising:
 providing a plurality of nanoparticles having a size of less than about 1000 nanometers comprising a polymeric core having an agent disposed within the polymer and at least one charged polymer layer;   providing a carrier; and   admixing the plurality of nanoparticles and the carrier.   
   
   
       10 . A method of making a recording medium comprising:
 providing a plurality of nanoparticles having a size of less than about 1000 nanometers comprising a polymeric core having at least one colorant disposed within the polymer and a protective coating disposed on and substantially covering the nanoparticle;   providing a carrier; and   admixing the nanoparticle and the carrier.   
   
   
       11 . A method of making a recording medium comprising:
 providing a plurality of nanoparticles having a size of less than about 1,000 nanometers and comprising a polymeric core having a positive or a negative zeta potential, a first charged polymer layer disposed on the core and having a zeta potential opposite the zeta potential of the core and at least one successive charged polymer layer disposed on the first charged polymer layer, wherein the zeta potential of the at least one successive charged polymer layer is opposite that of the charged polymer layer adjacent thereto;   providing a carrier; and   admixing the plurality of nanoparticles and the carrier.   
   
   
       12 . A method of making a recording medium comprising:
 providing a first solution comprising at least one polymer, at least one colorant, and a first solvent;   combining the first solution with a second solution comprising a second solvent in which the first solvent is substantially immiscible;   emulsifying the first and second solutions to produce a polymeric particle having the colorant disposed therein; and   suspending the resulting particle in a liquid medium.   
   
   
       13 . The method of making a recording medium of  claim 12 , wherein the colorant is disposed within the polymeric particle. 
   
   
       14 . The method of making a recording medium of  claim 12 , further comprising the step of isolating the particle. 
   
   
       15 . The method of making a recording medium of  claim 12 , wherein the at least one colorant comprises a dye. 
   
   
       16 . The method of making a recording medium of  claim 12 , wherein the at least one colorant is present in the polymeric particle from about 1 percent by weight to about 30 percent by weight. 
   
   
       17 . The method of making a recording medium of  claim 12 , wherein the polymer comprises an organic polymer, an inorganic polymer, semi-organic polymer, semi-inorganic polymer, an organometallic polymer, or a combination thereof. 
   
   
       18 . The method of making a recording medium of  claim 12 , wherein the polymer comprises polyisoprene, polybutadiene, poly(acrylonitrile-co-butadiene), poly(α-methyl styrene), poly(vinyl acetate), poly(vinyl alcohol), polystyrene, polyethylene, polypropylene, polymethylmethacrylate, or a combination thereof. 
   
   
       19 . The method of making a recording medium of  claim 12 , wherein polymer particle has a size of less than about 1,000 nanometers. 
   
   
       20 . The method of making a recording medium of  claim 12 , wherein polymer particle has a size of less than about 400 nanometers. 
   
   
       21 . The method of making a recording medium of  claim 12 , wherein the polymer particle has a size of less than about 100 nm. 
   
   
       22 . The method of making a recording medium of  claim 12 , wherein the nanoparticle has a zeta potential of about +20 mV or greater. 
   
   
       23 . The method of making a recording medium of  claim 12 , wherein the nanoparticle has a zeta potential of about +50 mV or greater.